U.S. Pat. No. 5,678,611 discloses a multilayer tube for use as a fuel line or vapor return or recovery line. The tube is composed of a thermoplastic outer tubing, a bonding layer, and an inner hydrocarbon barrier layer. When a multilayer tube with a bonding layer, such as that in U.S. Pat. No. 5,678,611, is used in a motor vehicle, the individual layers frequently delaminate (or separate from one another) after prolonged contact with fuel, oil, or antifreeze (which typically can be a mixture of water and alcohol); heating; or cooling.
There is a continuing need for multilayer tubes for use in motor vehicles which do not delaminate after prolonged contact with fuel, oil or antifreeze; heating; or cooling.